#define WinLeft 10
#define WinRight  70
#define WinTop 5
#define WinBottom 20
#define WinArea (WinRight-WinLeft)*\    /*加上反斜杠以表示續行*/
(WinBottom-WinTop)
#define int CHAR

main()
{
     printf("The area of the window is %d",WinArea);
}